ABSTRACT The Clinical Core will assist cystic fibrosis (CF) investigators at University of Washington and nationwide in translation of promising laboratory findings into new diagnostic or therapeutic approaches to improve the lives of patients with CF. The core builds upon an internationally recognized program in translational CF research which has been under the direction of Dr. Bonnie Ramsey for over 25 years. The core in conjunction with the Host Defense Core will assist investigators in multiple stages of clinical development including 1) preclinical processes such as drug formulation, animal toxicology studies and regulatory support, 2) clinical research plan development and 3) study implementation. There will also be significant emphasis on further expansion of an existing biorepository of microbial and human samples closely linked to all the P30 cores. Finally, there will be a robust research program directed towards development of novel statistical approaches and outcome measures for this finite population. There will also be a new focus to moving proven therapies into health practices, and encouraging its adoption as a standard approach with the addition of a focus on post-approval use of therapeutics and conduct comparisons of clinical approaches broadly defined as comparative effectiveness research (CER). The core will be further enhanced by close linkage with the services of the UW Institute of Translational Health Sciences [Clinical Translational Science Award (UL1RR025014) and the Clinical Core of the Cystic Fibrosis Foundation (CFF) supported Research Development Program (RDP) as well as the existing infrastructure within the CF Therapeutics Development Network Coordinating Center (TDNCC).